1. Technical Field
The present disclosure relates to a communication apparatus and a communication method to perform uplink transmission power control.
2. Description of the Related Art
In Task Group ax of the Institute of Electrical and Electronics Engineers (IEEE) 802.11 Working Group, a technical specification of IEEE 802.11ax (hereinafter, 11ax) is being developed as a next standard that would replace 802.11ac. In 11ax, a multi-user transmission method (hereinafter, MU transmission) based on the orthogonal frequency-division multiple access (OFDMA) and the multi user-multi input multi output (MU-MIMO) is expected to be introduced to uplink (UL).
In a UL MU transmission procedure, an access point (also called a base station) transmits a control signal as a trigger for an uplink signal to multiple stations (also called STAs) within the area covered by the access point. Based on the control signal, a station, which transmits the uplink signal, transmits an UL response signal (also called a UL response frame) to the access point. There are two methods for the UL MU transmission procedure: one in which an access point specifically designates a station and allocates a frequency resource (hereinafter, a resource unit (RU)) thereto; and the other in which a station selects the RU by a random access (RA). A trigger frame (TF) is a control signal by which the access point specifically designates a station and indicates a corresponding resource, and a trigger frame-random (TF-R) is a control signal by which the access point indicates at least one random access resource.
The TF-R includes allocation information for a station that secures the resource by the random access (hereinafter, random access allocation information) and allocation information for a station specifically designated for the resource allocation (hereinafter, specific allocation information). A station that transmits the UL response signal by the random access decodes RU information for the random access from the TF-R, selects one RU randomly from multiple random access RUs, and transmits the UL response signal using the selected RU (e.g., see IEEE 802.11-15/0132R12 “SPECIFICATION FRAMEWORK FOR TGAX”).